An essay published on July 14th in PLOS Pathogens' new "Research Matters" series reflects on a career path that started with the study of a somewhat obscure mouse virus mice and ended up at the frontline of the SARS and MERS ...

According to figures of the World Health Organization, some 8.7 million people contracted tuberculosis in 2012 and this disease is fatal for approximately 1.3 million people throughout the world each year. One of the main ...

It's a scary struggle. Forget guns, bullets, bombs and drones. Humans are entangled in a far more lethal world war than the conflicts often described in the news. The numbers and potential kill factors are frightening. Ebola ...

Prescribing patients two or more drugs that do not reach the same parts of the body could accelerate a pathogen's resistance to all of the drugs being used in treatment, according to a new study published today in the Proceedings ...

Changes in the gut bacteria of colon cancer patients indicate that some virulent bacteria could be linked to the progression of the disease, according to research published in the open access journal Genome Medicine. The ...

Garlic extract may be an effective weapon against multi-drug resistant strains of pathogenic bacteria associated with urinary tract infections (UTI), according to a recent study published in the Pertanika Journal of Tropical ...

The red, itchy rash caused by varicella-zoster - the virus that causes chickenpox - usually disappears within a week or two. But once infection occurs, the varicella-zoster virus, or VZV, remains dormant in the nervous system, ...

Antibiotic resistance, and multi-drug resistance, is a major public health threat. A new study publishing in PLOS Computational Biology finds conditions where restricting certain antibiotics may increase the frequency of ...

Zoonotic malaria has been shown to be caused by two genetically distinct Plasmodium knowlesi parasite subpopulations associated with different monkey host species in Malaysia, according to new research published in PLOS Pathogens. ...

Pathogen

A pathogen (from Greek πάθος path "suffering, passion", and γἰγνομαι (γεν-) gignomai (gen-) "I give birth to"), infectious agent, or (more commonly) germ, is a biological agent that causes disease or illness to its host. There are several substrates and pathways whereby pathogens can invade a host; the principal pathways have different episodic time frames, but soil contamination has the longest or most persistent potential for harboring a pathogen.

The body contains many natural defenses against some of the common pathogens (such as Pneumocystis) in the form of the human immune system and by some "helpful" bacteria present in the human body's normal flora. However, if the immune system or "good" bacteria is damaged in any way (such as by chemotherapy, human immunodeficiency virus (HIV), or antibiotics being taken to kill other pathogens), pathogenic bacteria that were being held at bay can proliferate and cause harm to the host. Such cases are called opportunistic infection.

Some pathogens (such as the bacterium Yersinia pestis, which may have caused the Black Plague, the Variola virus, and the Maleria protozoa) have been responsible for massive numbers of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV, which is known to have infected several million humans globally, along with the Influenza virus. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of vaccination, antibiotics, and fungicide, pathogens continue to threaten human life. Social advances such as food safety, hygiene, and water treatment have reduced the threat from some pathogens.

Not all pathogens are negative. In entomology, pathogens are one of the "Three P's" (predators, pathogens, and parasitoids) that serve as natural or introduced biological controls to suppress arthropod pest populations.